Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757230AbcDGRtt (ORCPT ); Thu, 7 Apr 2016 13:49:49 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:33448 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756645AbcDGRtr (ORCPT ); Thu, 7 Apr 2016 13:49:47 -0400 Subject: Re: [PATCH 1/2] pci: add pci_unmap_iospace function for PCI_IOBASE To: Bjorn Helgaas References: <1457389310-3538-1-git-send-email-okaya@codeaurora.org> <20160407160004.GA8780@localhost> Cc: linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, agross@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org From: Sinan Kaya Message-ID: <57069DB5.9060404@codeaurora.org> Date: Thu, 7 Apr 2016 13:49:41 -0400 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <20160407160004.GA8780@localhost> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3910 Lines: 109 On 4/7/2016 12:00 PM, Bjorn Helgaas wrote: > Hi Sinan, > > On Mon, Mar 07, 2016 at 05:21:49PM -0500, Sinan Kaya wrote: >> The PCI_IOBASE needs to be released after hotplug removal so that it can be >> re-added back by the pci_remap_iospace function during insertion. >> >> Adding unmap function to follow IO remap function. >> >> Signed-off-by: Sinan Kaya >> --- >> drivers/pci/pci.c | 25 +++++++++++++++++++++++++ >> include/linux/pci.h | 1 + >> 2 files changed, 26 insertions(+) >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 3a516c0..f5faed2 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -26,6 +26,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -3169,6 +3170,30 @@ int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) >> #endif >> } >> >> +/** >> + * pci_unmap_iospace - Unmap the memory mapped I/O space >> + * @virt_addr: virtual address to be unmapped >> + * @size: size of the physical address to be unmapped >> + * >> + * Unmap the CPU virtual address @virt_addr from virtual address space. >> + * Only architectures that have memory mapped IO functions defined >> + * (and the PCI_IOBASE value defined) should call this function. >> + */ >> +void __weak pci_unmap_iospace(struct resource *res) > > Why is this weak? I assume probably because pci_remap_iospace() is > weak, but I don't see any reason why *that* needs to be weak. There's > only one implementation. I think neither one should be weak unless we > have an actual need for that. > Right, copy paste mistake. Even the function parameter description above is not right. I can get rid of the __weak from both on the next iteration. >> +{ >> +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) >> + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; >> + >> + unmap_kernel_range(vaddr, resource_size(res)); > > There really aren't any other generic uses of unmap_kernel_range(). > This isn't an unusual scenario, so I would expect this code to use a > pattern that's used elsewhere. OK, What's the best way to remove a mapping? I'm open for suggestions. I copied this pattern from GHES driver. > >> +#else >> + /* >> + * This architecture does not have memory mapped I/O space, >> + * so this function should never be called. >> + */ >> + WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); >> +#endif >> +} >> + >> static void __pci_set_master(struct pci_dev *dev, bool enable) >> { >> u16 old_cmd, cmd; >> diff --git a/include/linux/pci.h b/include/linux/pci.h >> index 398ae7e..c6e3f0e 100644 >> --- a/include/linux/pci.h >> +++ b/include/linux/pci.h >> @@ -1172,6 +1172,7 @@ int pci_register_io_range(phys_addr_t addr, resource_size_t size); >> unsigned long pci_address_to_pio(phys_addr_t addr); >> phys_addr_t pci_pio_to_address(unsigned long pio); >> int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr); >> +void pci_unmap_iospace(struct resource *res); >> >> static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar) >> { >> -- >> 1.8.2.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Sinan Kaya Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project